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Replace 190/50 to 190/55 tire

17K views 30 replies 11 participants last post by  KevinT707 
#1 ·
My bike is 2015 CBR1000RR with stock rear tire size 190/50.
I plan to replace it to 190/55,
does any one know how much seat height will be changed?
Do I need to lower my rear suspension? Does 190/55 changed bike geometry.

Thanks
 
#6 ·
I don't think the bike geometry will change just the back end of the bike will sit higher. This means you are tilted more forward when riding and put more weight on the handle and front tyre hence the "better" turn in. You would probably get the same result by raising your seat.

On the other hand higher profile will give more flex on the side walls hence more comfort but at the expense of steering sharpness (front wheels i.e). This is certainly my experience with car tyres. How that works in the case a bike, I don't know for sure
 
#8 ·
While you qualified your statement with the line about not actually knowing about motorcycles I am of the opinion that in times like these you just keep quiet and let people that do know the answers talk. When you give inaccurate information to people about handling aspects of a motorcycle you can get people hurt.

Changing tire sizes does alter the geometry of the motorcycle and tuned Flex in the sidewall is critical in the design of motorcycle tires for grip at lean. Current race tires with super tall side walls run as little as 19psi cold in the rear that works in conjunction with overly stiff side walls designed specifically for those low pressures.
 
#11 ·
LDH forums are places where people exchange views, opinions and experiences. we are not all experts or work for tyre companies ~(in fact do you?). So chill out pal!

I referred to a parallel situation when it came to cars but stated that I did not know the effect on bikes (which your reply seems to confirm)

It would be more constructive if you just chime in explaining properly for the benefit of other members
 
#19 ·
My issues with the 190/55 is that I'm short, but I think I was able to dial things in well. I lowered the bike 1" in the rear and 1/2" in the front, the suspension settings are pretty in tune albeit with stock equipment. I don't feel a significant change in the ride, but I am not dragging knee on the street. I'm only 5'3 I just need a wee bit lower so I could maneuver the bike better.
 
#21 ·
I installed the roaring toyz adjustable lowering link. I'd seen too many failures with the screw type.
 
#22 ·
Geometry is critical on sportbikes and what you have done by lowering it is basically completely ruined the handling. All it is good for now is cruising up and down the street to Starbucks or drag racing in a straight line only which is fine if that is what you are into, but for sport type riding in the twisties or the track you have created a very dangerous situation as the bike is going to fight you both into and out of the turns instead of altering the geometry in a way that naturally allows it to tip into the turns on the brakes (trailbraking) and hold a line on the way out without running wide. You have also reduced ground clearance so parts will drag much easier now as well.
 
#23 ·
I know. I really do. I am a proponent of not lowering the bike 99% of the time. When I go back to a stock size tire I may then put it back to stock height. Do you have any other suggestions to getting the bike lower that wouldn't have such an ill effect?

Could you help explain why going from a 190/50 to 190/55 doesn't cause the same kind of negative effect as lowering with a link or plates?
 
#25 ·
1. The change from a 190/50 tire to a 190/55 tire is pretty negligible. At most it might be 16mm of difference in diameter which you divide by half so maybe 8mm of ride height change at the axle.

2. That 8mm of change is at the axle and most importantly it is making the bike TALLER not shorter.

3. Changing the ride height at or with the progressive rate linkage makes a MUCH more drastic difference to the ride height. For example to get that same 8mm of ride height change at the axle that you got by changing tire sizes you would only need to add or remove maybe 2mm of additional length at the shock clevis. 2mm at the shock clevis by the time it gets to the rear axle is usually 3-4x as much change.

4. When you alter the link plates or dog bones of the rising rate suspension then you are also changing that rising rate which in many cases is a very bad thing when it comes to improving the handling of the bike not even taking into account what you have done to the geometry.

5. My geometry/suspension intro page http://www.rogueracing.org/geometry.htm
 
#27 ·
2. That 8mm of change is at the axle and most importantly it is making the bike TALLER not shorter.

3. Changing the ride height at or with the progressive rate linkage makes a MUCH more drastic difference to the ride height. For example to get that same 8mm of ride height change at the axle that you got by changing tire sizes you would only need to add or remove maybe 2mm of additional length at the shock clevis. 2mm at the shock clevis by the time it gets to the rear axle is usually 3-4x as much change.

4. When you alter the link plates or dog bones of the rising rate suspension then you are also changing that rising rate which in many cases is a very bad thing when it comes to improving the handling of the bike not even taking into account what you have done to the geometry.

5. My geometry/suspension intro page http://www.rogueracing.org/geometry.htm
I sat on a few bikes with stock tire size and some with the 55, the 55 did feel a lot taller, of course I don't know what any of the other suspension settings were like.

#2 - I understand that, and I think that's part of the point especially with things like the larger profile tire, and/or the Lee's link.

#3 what are my options here? Ohlins? Are there any suspension adjustments I could make on the stock suspension?

#4 makes sense

#5 Reading it now!
 
#26 ·
For the record I am really short myself and most of my trackbikes and especially my 04-07 1000RR's were really tall on the front so I could only stand on one foot at any give time. That's just what I learned to do, tippy toe all the time as once you are in motion none of that matters...
 
#29 ·
I realize this is an old thread, but it was the most recent I could find. The search feature did not help as it appears to order the results in a random, unchangeable manner.

I started riding the street again recently after a few years racing 600's about a decade ago. Jumping on the CBR1000RR the first thing I noticed was how heavy it was to steer. I understood there was not much weight difference from a 600, but the rear tire was a 190/50 and had a slightly more rounded profile than the 600's 180/55 (rogue racing link). The rideability of the bike was horrible (to me), but after seeing the illustration of the different tire profiles I decided to go with a 190/55 in the new Dunlop Q3+.

Long story short, I finally had a chance to ride the bike with the new tires. All I can say is WOW. It is a completely different bike. I was beginning to doubt my riding ability as it was almost scary to lean the bike over previously, but now it leans as you would expect and changes direction effortlessly. It's a completely different bike, and I'm pleasantly surprised by the new handling characteristics, it's actually fun to ride. I look forward to hitting the canyons soon.

I wanted to post this up because as I was deciding I read a lot of dissenting views of the 190/55 tire which had me sitting on the fence. However after researching the tire profile and remembering how nicely the 600 would turn I decided to take a chance. The only downside is that it is a little taller and will affect your speedo reading, showing a slower-than-actual speed. I already had a SpeedoDRD because I went -1 in the front, so removing 4.1% from the sprockets' -6.7% change did the trick (it is actually a little more than a 4.1% difference, right now it reads the exact speed while previously the speedo read 1 mph faster always).

Hope this helps someone who is deciding whether or not to make the switch.
 
#31 ·
I realize this is an old thread, but it was the most recent I could find. The search feature did not help as it appears to order the results in a random, unchangeable manner.

Hope this helps someone who is deciding whether or not to make the switch.
I'm glad you trusted the forums and went with the majority on this one. It's the only way to go. Enjoy yourself!
 
#30 ·
I'm glad you did, Liquid. This is one of the necro threads I visited before deciding on a 190/55.
I haven't had it out yet because I went a little mod stupid at once

I did the 06 swing arm (mainly because I wanted it in black) with the dog bone (for the extra 1/4" according to Speedy's garage), shock (because the 06 is more my weight band than the 04), and link. It came with a lowering link but I left it at factory length to start.
 
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